In the past, a number of systems have been developed in an attempt to determine the position of a railway vehicle moving along a track. Early detection systems involved the use of track mounted switches or transducers which were activated by a passing railway vehicle to provide a position signal to a central station. Railway vehicle navigation systems became more sophisticated with the advent of the computer and satellite global positioning systems (GPS). Now a rapid response navigation system could be mounted on the railway vehicle to provide sequential position data as the vehicle moved along a route. The inputs to such navigation systems could involve speed and distance data from a wheel tachometer, a GPS position indicator, and sometimes sensed track anomalies occurring along the route for comparison with anomalies for the same route previously stored in a navigation computer.
Even the more sophisticated railroad vehicle navigation systems experience difficulty in providing accurate, real time information relative to the movement of a rail vehicle through turnouts, crossovers and other trackwork involving a plurality of parallel and/or intersecting tracks. However, the need to detect in real time changes of track is critical to rail navigation, for only by accurately and reliably determining which track a railway vehicle is on can safety be assured.
It is a primary object of the present invention to provide a novel and improved method and apparatus for detecting in real time movement of a rail vehicle through turnouts, crossovers and other trackwork involving a plurality of parallel and/or intersecting tracks.
Another object of the present invention is to provide a novel and improved multi-sensor route detector for rail vehicle navigation which employs at least three track rail sensors with a center track rail sensor mounted on a railroad vehicle so as to be positioned between the tracks over which the vehicle moves and a left and right track rail sensor mounted on the railroad vehicle so as to be spaced outwardly on either side of the track.
Yet another object of the present invention is to provide a novel and improved multi-sensor route detector for rail vehicle navigation which employs a truck angle sensor to provide an output indicative of the movement of a railway vehicle truck relative to the longitudinal axis of the railway vehicle body or frame.
A further object of the present invention is to provide a novel and improved multi-sensor route detector for rail vehicle navigation which employs the combined outputs of right, left and central track sensors and a truck angle sensor to detect in real time movement of a railroad vehicle through turnouts, crossovers and trackwork involving a plurality of parallel and/or intersecting tracks.
A still further object of the present invention is to provide a novel and improved method for rail vehicle route detection which includes obtaining a detection output pattern from rail detection sensors mounted on a railroad vehicle as the vehicle moves through turnouts, crossovers and trackwork involving a plurality of parallel and/or intersecting tracks along a rail vehicle route and comparing these patterns with previously detected and stored patterns for turnouts, crossovers and a plurality of parallel or intersecting tracks along the same route.
These and other objects of the present invention are achieved by providing a multi-sensor route detector for rail vehicle navigation which includes at least three sensors for detecting the presence of metal rails. These sensors are mounted on a railway vehicle with one central sensor positioned between tracks over which the vehicle moves and two sensors positioned in spaced relation outboard on opposite sides of the track. These rail detecting sensors sense different rail crossing configurations as the railway vehicle moves into and through turnouts, crossovers and trackwork involving a plurality of parallel and/or intersecting tracks and provides output signature patterns unique to each. Signal processing and signal conditioning equipment receives and compares the output signature patterns from the rail detecting sensors with previously stored signature patterns of all possible turnout geometries along the route in the general area of interest and determines which route the railway vehicle took through the turnout.